• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.39-47
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• 2011

The motion of a conductive spherical particle under uniform electric field is investigated in order to find a suitable method for removing the conducting solid impurities contained in liquid plastic. When the positive dc voltage applied to the upper electrode, the vertical up-and-down motion of a charged particle by electrostatic force is observed by a charge-coupled device (CCD) camera or a high-speed video camera. The experimental data of the static threshold voltage by which the particle starts to move toward the counter electrode in air or silicone oil are in good agreement with theoretical value. When the applied voltage is larger than the static threshold voltage, the particle motion pattern in silicone oil consists of four stages: upward motion, stopping at the upper electrode, downward motion and stopping at the lower electrode. The stopping motion on the electrode is thought to be caused by the liquid flow accompanied by the particle motion. The particle charge calculated by integrating the pulse current, which is generated by the charge exchange between the electrode and the particle, is approximately 0.1~0.25 times of the theoretical value. This study is expected to help understand the electric properties of microparticles in oil circuit breaker (OCB) and oil transformer and improve their performance and longevity.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.105-108
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• 2004

This paper describes the influence of conducting particle in the coaxial cylindrical electrodes under alternating voltage condition investigated using breakdown electric field and electro magnetics simulation method. Simulated particle-location in GIS chamber were the particle on electrode, the particle on enclosure and free moving particle. As results, it was founded that in case of breakdown electric field of the GIS chamber, breakdown electric field of particle on electrode was the lowest, that of free moving particle was middle and that of particle on enclosure was the highest. And in case of the electric field analysis with particle locations, electric field of particle on electrode was the highest that of lifted particle was middle and that of particle on enclosure was the lowest. This results can offer a practical reference ra the insulation design of domestic GIS.

• Journal of Soil and Groundwater Environment
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• v.23 no.6
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• pp.104-113
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• 2018

A three-dimensional electrochemical process using nanosized zero-valent iron (NZVI)/activated carbon (AC) particle electrode and persulfate (PS) was developed for oxidizing pollutants. X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were performed to characterize particle electrode. XRD and SEM-EDS analysis confirmed that NZVI was impregnated on the surface of AC. Compared with the conventional two-dimensional electrochemical process, the three-dimensional particle electrode process achieved three times higher efficiency in phenol removal. The system with current density of $5mA/cm^2$ exhibited the highest phenol removal efficiency among the systems employing 1, 5, and $10mA/cm^2$. The removal efficiency of phenol increased as the Fe contents in the particle electrode increased. The particle electrode achieved more than 70% of phenol removal until it was reused for three times. The sulfate radical played a predominant role in phenol removal according to the radical scavenging test.

• Particle and aerosol research
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• v.14 no.3
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• pp.81-88
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• 2018

The market for improving the indoor air quality is continuously increasing, and air cleaners are the representative products. As interest in indoor air quality increases, so are the ultrafine particle which are harmful to the human body. Despite its many advantages, electrostatic precipitators are less used in indoor air due to ozone production. In this study, the carbon fiber sheet was applied to the discharge electrode and compared with the conventional tungsten wire discharge electrode. The particle collection efficiency and the amount of ozone generation were measured for 10-100 nm particles. Furthermore, it was applied to commercial air purifier with electrostatic precipitator to compare particle removal performance. The carbon fiber sheet type discharge electrode generates a small amount of ozone, and thus it can be applied to improve indoor air quality.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.5
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• pp.14-19
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• 2001

This paper describes the influence of conducting particle in the coaxial cylindrical electrodes under alternating voltage condition investigated using breakdown electric field and electro magnetics simulation method. Simulated particle-location in GIS chamber were the particle on electrode, the particle on enclosure and free moving particle. As results, it was founded that in case of breakdown electric field of the GIS chamber, breakdown electric field of particle on electrode was the lowest, that of free moving particle was middle and that of particle on enclosure was the highest. And in case of the electric field analysis with particle locations, electric field of particle on electrode was the highest, that of lifted particle was middle and that of particle on enclosure was the lowest. This results can offer a practical reference on the insulation design of domestic GIS.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.111-112
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• 2000

The breakdown characteristics of surface discharge investigated experimentally agree well with the analytic results of previous reports [1-3] in various electrode geometries. Additionally, we find that the electrode geometry effects on the firing voltage can be understood with the ionization probability relating to the number of priming particles. We have also observed the shape of surface discharge and the surface striations in the gap geometry with the pressure, the applied voltage, and the driving frequency.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.130-133
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• 2002

Solder leaching resistance of the metal electrode is an important factor with regard to adhesion properties of ceramic substrate. In the Low Temperature Co-fired Ceramics (LTCC), Ag-Pd or Ag-Pt pastes are used instead of pure Ag paste to prevent leaching. Solder leaching behavior of the Ag-Pd paste in relation to LTCC raw material powder size was investigated. First fabrication of LTCC green tape with different particle size was done. LTCC substrates with Ag-Pd electrode were prepared using conventional multilayer ceramic process. Dipping test was performed to test solder leaching behavior of the electrode. Ag-Pd electrode on LTCC substrate with smaller particle size achieved higher solder leaching resistance.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1536-1539
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• 1994

The influence due to metallic particle contaminated on spacer surface is remarkable in the decreasing of dielectric strength in $SF_6$ GIS. In relation with this problem, We studied, AC flash-over voltage characteristics and breakdown mechanism are investigated under metallic particle initiated condition in $SF_6$ gas by varying the particle position, particle shape with a plane-plane electrode. The main results arc as follows 1. The small amount of the metallic particle in the gap do not make flash-over voltage to be influence, but the significant decrease of th flash-overed voltage is result in case of the big and long size of the metallic paraticle. 2. Influence of the flash-over voltage are lowest in the mid and are highest in the electrode of metallic particle position. 3. In case of the initiated metallie particle, The more the pressure are high, the more the recluced ratio of flash-over voltage are high. 4. The metallic particle shape which results in the reduced flash-over voltage forced the critical pressure to move in to the region of low pressure. 5. The existance of the metallic particle on the upper electrode side and high pressure make the decreasing ratio of flash-over voltage bigger than that of the ground side electrode.

• Particle and aerosol research
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• v.14 no.4
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• pp.121-133
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• 2018

In this study, we developed a flat-plate type wet electrostatic precipitator that generates stable corona discharge compared to wire type discharge electrode. In order to compare the particle removal efficiency according to the shape of the discharge electrode such as the variation of the horizontal and vertical distance between spiked edges, and the variation of the height of discharge pin support were tested. As a result, when the horizontal distance between spiked edges was increased up to 36 mm, the vertical distance between spiked edges was increased up to 54 mm, and the height of the discharge pin support was increased up to 76 mm, the removal efficiency of PM10 was maintained at approximate 60.0%. Furthermore, the removal efficiency of particles over $5{\mu}m$ was about 80% or more. When the flow rate was 4 m/s, the gap between collection plates was 60 mm, and -14 kV was applied to the discharge electrode. The particle removal efficiency of the flat-plate type electrostatic precipitator was maintained when the horizontal and vertical distance between spiked edges, and the height of the discharge pin support was below a certain level. Those variables may be the important design factors for the shape of the discharge electrode. Therefore, when designing the electrostatic precipitator with multiple channels, the horizontal and vertical distance between spiked edges, and the height of discharge pin support must be selected in consideration of the weight of the discharge electrode and the processing cost.

• Journal of Environmental Science International
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• v.6 no.1
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• pp.1-8
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• 1997

Varing the flow velocity of solution and particle diameter, the mass transfer coefficient of the local electrode on current feeder has been measured in an empty flow reactor, an inert fluidized bed electrode reactor, and an active fluidized bed electrode reactor. It had its maximium value when the bed porosity was 0.6 to 0.65 and decreased with in- creasing the height of local electrode. The mass transfer coefficient was found to be high especially when higher particle was fluidized. Electrochemical deposition of copper dissolved in the synthesized wastewater has been performed in the active fluidized bed electrode reactor. The deduction rate was higher than 90% and the residual concentration of copper decreased to less than 5ppm.